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A facile and universal route for synthesizing transition metal borides has been developed by reaction of boron triiodide (BI3) with elemental transition metals. This method employs relatively low synthesis temperatures to afford single-phase samples of various binary and ternary metal borides, such as Fe2B, Co2B, Ni3B, TiB2, VB2, CrB2, and Ni2CoB. This synthesis protocol can be utilized for the topotactic transformation of metal shapes into their respective borides, as exemplified by transformation of Ni foam to Ni3B foam. In situ powder X-ray diffraction studies of the Ni–BI3 system showed that the crystalline nickel borides, Ni4B3 and Ni2B, start to form at temperatures as low as 700 K and 877 K, respectively, which is significantly lower than the typical synthesis temperatures required to produce these borides. Ni3B synthesized by this method was tested as a supporting material for oxygen evolution reaction (OER) in acidic media. Composite electrocatalysts of IrO2/Ni3B with only 50% of IrO2 exhibit current densities and stability similar to pure IrO2 at mass loadings lower than 0.5 mg cm−2, indicating Ni3B could be a promising supporting material for acidic OER. [ABSTRACT FROM AUTHOR]

Fluoride-doped TiO2 (F-TiO2) was synthesized by an efficient and simple one-step synthesis and successfully used for the UV-photo-degradation of the toxic and stable pollutants methylene blue (MB) and bisphenol A (BPA). Initially, the synthesized catalyst was characterized and compared to untreated TiO2 (P25 Degussa) by different physical–chemical analyses such as XRD, band gap calculation, SEM, EDS, FITR, ECSA, or EIS. F-TiO2 defeated commercial TiO2, and almost complete pollutant removal was achieved within 30 min. The energy consumption was reduced as a result of the suitable reactor set-up, which reduced light scattering, and by the application of a long-pulse radiation procedure, where the lamp was switched off during periods where the radical degradation continued. This enhanced the overall photocatalysis process performance. Under these conditions, 80% of MB removal was attained within 15 min radiation with an energy consumption of only 0.070 Wh min−1, demonstrating a much better efficiency when compared to previously reported data. The catalyst was reusable, and its performance can be improved by the addition of H2O2. The results were validated by BPA degradation and the treatment of real wastewaters with both pollutants. The results were so encouraging that a scale-up reactor has been proposed for future studies. [ABSTRACT FROM AUTHOR]

We investigate LaCo 2 P 2 as an electrocatalytic material for oxygen evolution reaction (OER) under alkaline and acidic conditions. This layered intermetallic material was prepared via Sn-flux high-temperature annealing. The electrocatalytic ink, prepared with the ball-milled LaCo 2 P 2 catalyst at the mass loading of 0.25 mg/cm 2 , shows OER activity at pH = 14, reaching current densities of 10, 50, and 100 mA/cm 2 under the overpotential of 400, 440, and 460 mV, respectively. Remarkably, the electrocatalytic performance remains constant for at least 4 days. Transmission electron microscopy reveals the formation of a catalytically active CoO x shell around the pre-catalyst LaCo 2 P 2 core during the alkaline OER. The core serves as a robust support for the in situ -formed electrocatalytic system. Similar studies under pH = 0 reveal the rapid deterioration of LaCo 2 P 2 , with the formation of LaPO 4 and amorphous cobalt oxide. This study shows the viability of layered intermetallics as stable OER electrocatalysts, although further developments are required to improve the electrocatalytic performance and increase the stability at lower pH values.